At Wren Station High School, there are x physics teachers and y chemistry teachers. The total number of chemistry and physics teachers together is 7. The number of chemistry teachers is 1 fewer than three times the number of physics teachers.
By 1st condition, x+y=7 --eqn. 1 By 2nd condition, 3x-y=1 --eqn. 2 By solving the two equations we get 4x = 8 Therefore x=2 Substituting in eqn. 1 2+y=7 y=7-2 Therefore y=5 x=2, y=5
